Multi zone spot heating in epi

ABSTRACT

Embodiments of the present disclosure generally relate to apparatus and methods for semiconductor processing, more particularly, to a thermal process chamber. The thermal process chamber includes a substrate support, a first plurality of heating elements disposed over or below the substrate support, and a spot heating module disposed over the substrate support. The spot heating module is utilized to provide local heating of cold regions on a substrate disposed on the substrate support during processing. Localized heating of the substrate improves temperature profile, which in turn improves deposition uniformity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 17/331,401, filed May 26, 2021 which is adivisional of and claims priority to U.S. patent application Ser. No.16/170,255, filed Oct. 25, 2018, now patented as U.S. Pat. No.11,021,795, patent date Jun. 1, 2021, which claims the benefit of U.S.Provisional Patent Application Ser. No. 62/578,850, filed on Oct. 30,2017, all of which herein are incorporated by reference.

BACKGROUND Field

Embodiments of the present disclosure generally relate to apparatus andmethods for semiconductor substrate processing, more particularly, to athermal process chamber useful for semiconductor substrate processing.

Description of the Related Art

Semiconductor substrates are processed for a wide variety ofapplications, including the fabrication of integrated circuit devicesand microdevices such as MEMS. In one known process apparatus fordepositing a layer of material on the substrate, during processing ofthe substrate, the substrate is positioned on a susceptor within aprocess chamber. The susceptor is supported by a support shaft, which isrotatable about a central axis to rotate the susceptor attached to oneend thereof. Precise control of a heating source, such as a plurality ofheating lamps disposed below and above the substrate, allows thesubstrate to be heated during processing thereof to within a very stricttolerance range. The temperature of the substrate can affect theuniformity of the material deposited on the substrate.

Despite the precise control of the heat source used to heat thesubstrate, it has been observed that valleys (lower deposition layerthickness regions) are formed at certain locations on the substrate.Therefore, a need exists for a thermal process chamber for semiconductorprocessing capable of improved control of the uniformity of thesubstrate temperature.

SUMMARY

Embodiments of the present disclosure generally relate to apparatus andmethods for semiconductor substrate processing, more particularly, to athermal process chamber useful for semiconductor substrate processing.In one embodiment, a process chamber includes a chamber body, asubstrate support disposed in the chamber body, a radiant moduledisposed outside the chamber body facing the substrate support, asupport disposed outside the chamber body, a mounting bracket disposedon the support, and a spot heating module coupled to the mountingbracket.

In another embodiment, a process chamber includes a chamber body, asubstrate support disposed in the chamber body, a support disposedoutside the chamber body, a mounting bracket disposed on the support,and a spot heating module coupled to the mounting bracket. The spotheating module includes a movable stage coupled to the mounting bracket.

In another embodiment, a process chamber includes a chamber body, asubstrate support disposed in the chamber body, a support disposedoutside the chamber body, a mounting bracket disposed on the support,and a spot heating module coupled to the mounting bracket. The spotheating module includes at least one adjustable wedge.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 is a schematic side view of an apparatus according to oneembodiment.

FIG. 2 is a schematic cross sectional side view of a process chamberaccording to one embodiment.

FIG. 3 is a schematic cross sectional side view of a process chamberaccording to another embodiment.

FIG. 4 is a schematic cross sectional side view of a process chamberaccording to a yet another embodiment.

FIG. 5 is a schematic cross sectional side view of a process chamberaccording to a yet another embodiment.

FIGS. 6A-6B are schematic top views of a spot heating module accordingto the embodiments.

FIGS. 7A-7B are perspective views of a mounting bracket for mounting thespot heating module of FIGS. 6A-6B according to embodiments.

FIG. 8 is an exploded view of the mounting bracket of FIGS. 7A-7Bsecured to components of a process chamber according to one embodiment.

FIG. 9 is a schematic top view of the spot heating module of FIGS. 6A-6Bmounted to a process chamber according to one embodiment.

FIG. 10 is a schematic side view of a spot heater according to oneembodiment.

FIGS. 11A-11B are schematic views of a beam spot formed by one or morespot heaters of FIG. 10 according to one embodiment.

FIGS. 12A-12B are schematic views of a beam spot having differentorientations with respect to the movement of a substrate according toone embodiment.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized in other embodiments withoutspecific recitation thereof with respect thereto.

DETAILED DESCRIPTION

Embodiments of the present disclosure generally relate to apparatus andmethods for semiconductor processing, more particularly, to a thermalprocess chamber. The thermal process chamber includes a substratesupport, a first plurality of heating elements disposed over or belowthe substrate support, and a spot heating module disposed over thesubstrate support. The spot heating module is utilized to providelocalized heating of a substrate disposed on the substrate supportduring processing. The localized heating described herein improvesthermal uniformity across a substrate disposed on the substrate supportduring processing, which in turn improves deposition uniformity.

A “substrate” or “substrate surface,” as described herein, generallyrefers to any substrate surface upon which processing is performed. Forexample, a substrate surface may include silicon, silicon oxide, dopedsilicon, silicon germanium, germanium, gallium arsenide, glass,sapphire, and any other materials, such as metals, metal nitrides, metalalloys, and other conductive or semi-conductive materials, depending onthe application. A substrate or substrate surface may also includedielectric materials such as silicon dioxide, silicon nitride,organosilicates, and carbon dopes silicon oxide or nitride materials.The substrate itself is not limited to any particular size or shape.Although the embodiments herein are generally related to round 200 mm or300 mm substrates, other shapes, such as polygonal, square, rectangular,curved, or otherwise non-circular workpieces may be utilized.

FIG. 1 is a schematic side view of an apparatus 100 according to oneembodiment. The apparatus 100 includes a process chamber 102 and one ormore high-energy radiant sources 106. The process chamber 102 may be adeposition or a thermal treatment chamber, such as a vapor phase epitaxychamber, a rapid thermal process chamber, or a thermal treatmentchamber. The process chamber 102 includes a spot heating module 104, andthe spot heating module 104 is optically connected to the one or morehigh-energy radiant sources by one or more optical fibers 108.

The spot heating module 104 includes one or more spot heaters 110, andeach spot heater 110 is connected to a high-energy radiant source 106via a corresponding optical fiber 108. In one embodiment, a singleradiant source 106 is optically coupled to more than one spot heater bya plurality of optical fibers 108, so that one laser source is providingenergy for multiple spot heaters 110. In another embodiment, each spotheater 110 is coupled to a corresponding radiant source 106 by anoptical fiber 108.

The one or more high-energy radiant sources 106 are part of the spotheating module 104. For example each spot heater 110 may include ahigh-energy radiant source 106. The one or more high-energy radiantsources 106 may be focused high-energy radiant source, such as lasers.Examples of laser sources that may be used include crystal lasers, laserdiodes and arrays, and VCSEL's. High intensity LED sources may also beused. Wavelength of the emitted radiation may generally be in theultraviolet, visible, and/or infrared spectrum, from about 200 nm toabout 900 nm, for example, 810 nm, and the emitted radiation may bemonochromatic, narrow band, broadband, or ultra-broadband such as awhite laser. The one or more high-energy radiant sources 106 produce oneor more high-energy radiant beams, such as focused high energy radiantbeams, for example, laser beams, in order to perform localized, or spot,heating of the substrate disposed in the process chamber 102 during thethermal processing thereof.

FIGS. 2 and 3 illustrate a schematic sectional view of a process chamber200 according to one embodiment. The process chamber 200 may be theprocess chamber 102 shown in FIG. 1 . The process chamber 200 may beused to process one or more substrates therein, including the processesof depositing a material on a device side 250 of a substrate 202,heating of the substrate 202, etching of the substrate 202, orcombinations thereof. The process chamber 200 generally includes achamber wall 248, and an array of radiant heating lamps 204 for heating,among other components, a susceptor 206 disposed within the processchamber 200. As shown in FIG. 2 and FIG. 3 , an array of radiant heatinglamps 204 may be disposed below (i.e. facing the non-device side of) thesusceptor 206. As shown in FIG. 3 , an array of radiant heating lamps204 may be disposed below and/or above the susceptor 206. The susceptor206 may be a disk-like substrate support as shown, or may include aring-like substrate support (not shown), which supports the substrate202 from the edge of the substrate to expose a backside of the substrate202 directly to heat from the radiant heating lamps 204. The susceptor206 may be fabricated from silicon carbide or graphite coated withsilicon carbide to absorb radiant energy from the lamps 204 and conductthe radiant energy to the substrate 202, thus heating the substrate 202.

The susceptor 206 is located within the process chamber 200 between afirst energy transmissive member 208, which may be a dome, and a secondenergy transmissive member 210, which may also be a dome. The firstenergy transmissive member 208 and the second energy transmissive member210, along with a body 212 that is disposed between the first energytransmissive member 208 and second energy transmissive member 210,generally define an internal region 211 of the process chamber 200. Eachof the first energy transmissive member 208 and/or the second energytransmissive member 210 may be convex and/or concave. In someembodiments, each of the first energy transmissive member 208 and/or thesecond energy transmissive member 210 may be optically transparent tothe high-energy radiant radiation (transmitting at least 95% of theradiation of the high-energy radiant radiation). In one embodiment, thefirst energy transmissive member 208 and the second energy transmissivemember 210 are fabricated from quartz. In some embodiments, the array ofradiant heating lamps 204 may be disposed above the first energytransmissive member 208, for example, a region 239 defined between thefirst energy transmissive member 208 and a reflector 254 (discussedinfra), as shown in FIG. 3 . In some embodiments, the array of theradiant heating lamps 204 may be disposed adjacent to and beneath thesecond energy transmissive member 210. The radiant heating lamps 204 maybe independently controlled in zones in order to control the temperatureof various regions of the substrate 202 as a process gas or vapor passesover the surface of the substrate 202, thus facilitating the depositionof a material onto the device side 250 of the substrate 202. While notdiscussed here in detail, the deposited material may include elementalsemiconductor materials such as silicon, doped silicon, germanium, anddoped germanium; semiconductor alloys such as silicon germanium anddoped silicon germanium; and compound semiconductor materials, includingIII-V materials, examples of which include nitrides, phosphides, andarsenides of aluminum, gallium, indium, and thallium, and mixturesthereof, and II-VI materials, examples of which include sulfides,selenides and tellurides of zinc, cadmium, and mixtures thereof.

The radiant heating lamps 204 may provide a total lamp power of betweenabout 10 KW and about 60 KW, and are configured to heat the substrate202, for example to a temperature within a range of about 200 degreesCelsius to about 1,600 degrees Celsius. Each lamp 204 can be coupled toa power distribution board, such as printed circuit board (PCB) 252,through which power is supplied to each lamp 204. In one embodiment, theradiant heating lamps 204 are positioned within a housing 245 which isconfigured to be cooled during or after processing by, for example,using a cooling fluid introduced into channels 249 located between theradiant heating lamps 204.

The substrate 202 is transferred into the process chamber 200 andpositioned onto the susceptor 206 through a loading port (not shown)formed in the body 212. A process gas inlet 214 and a gas outlet 216 areprovided in the body 212.

The susceptor 206 includes a shaft or stem 218 that is coupled to amotion assembly 220. The motion assembly 220 includes one or moreactuators and/or adjustment devices that provide movement and/oradjustment of the position of the stem 218 and/or the susceptor 206within the internal region 211. For example, the motion assembly 220here includes a rotary actuator 222 that rotates stem 218, and thus thesusceptor 206, about the longitudinal axis A of the process chamber 200perpendicular to an X-Y plane of the process chamber 200. The motionassembly 220 also includes a vertical actuator 224 to move the stem 218,and thus susceptor 206, in the Z direction (e.g. vertically) within theprocess chamber 200. The motion assembly 220 optionally includes a tiltadjustment device 226 that is used to adjust the planar orientation ofthe susceptor 206 in the internal region 211. The motion assembly 220optionally also includes a lateral adjustment device 228 that isutilized to adjust the positioning of the stem 218 and/or the susceptor206 in the x-y plane of the process chamber 200 within the internalregion 211. In one embodiment, the motion assembly 220 includes a pivotmechanism 230.

The susceptor 206 is shown in an elevated processing position but islifted or lowered vertically by the motion assembly 220 as describedabove. The susceptor 206 is lowered to a transfer position (below theprocessing position) to allow lift pins 232 to contact standoffs 234 onor above the second energy transmissive member 210. The stand-offsprovide one or more surfaces parallel to the X-Y plane of the processchamber 200 and help to prevent binding of the lift pins 232 that mayoccur if the end thereof is allowed to contact the curved surface of thesecond energy transmissive member 210. The stand-offs 234 are made of anoptically transparent material, such as quartz, to allow energy from thelamps 204 to pass therethrough. The lift pins 232 are suspended in holes207 in the susceptor 206, and as the susceptor 206 is lowered and thebottom of the lift pins 232 engage the standoffs 234, further downwardmovement of the susceptor 206 causes the lift pins 232 to engage thesubstrate 202 and hold it stationary as the susceptor 206 is furtherlowered, and thus support the substrate off of the susceptor 206 fortransfer thereof from the process chamber 200. A robot (not shown) thenenters the process chamber 200 to engage at least the underside of thesubstrate 202 and remove the substrate 202 therefrom though the loadingport. A new substrate 202 may then be loaded onto the lift pins 232 bythe robot, and the susceptor 206 may then be actuated up to theprocessing position to place the substrate 202 thereon, with its deviceside 250 facing up. The lift pins 232 include an enlarged head allowingthe lift pins 232 to be suspended in openings in the susceptor 206 whenin the processing position. The susceptor 206, while located in theprocessing position, divides the internal volume of the process chamber200 into a process gas region 236 above the susceptor 206, and a purgegas region 238 below the susceptor 206. The susceptor 206 is rotatedduring processing using the rotary actuator 222 to minimize the effectof thermal and process gas flow spatial anomalies within the processchamber 200 and thus facilitates uniform processing of the substrate202. The susceptor 206 here rotates at between about 5 RPM and about 100RPM, such as between about 10 RPM and about 50 RPM, for example about 30RPM.

Substrate temperature is measured by sensors configured to measuretemperatures at the bottom of the susceptor 206. The sensors may bepyrometers (not shown) disposed in ports formed in the housing 245.Additionally or alternatively, one or more sensors 253, such as apyrometer, are used to measure the temperature of the device side 250 ofthe substrate 202. A reflector 254 may be optionally placed outside thefirst energy transmissive member 208 to reflect infrared light that isradiating off the substrate 202 and redirect the energy back onto thesubstrate 202. The reflector 254 here is secured to the first energytransmissive member 208 using a clamp ring 256. The reflector 254 can bemade of a metal such as aluminum or stainless steel. The sensors 253 canbe disposed through the reflector 254 to receive radiation from thedevice side 250 of the substrate 202.

Process gas supplied from a process gas supply source 251 is introducedinto the process gas region 236 through the process gas inlet 214 formedin the sidewall of the body 212. The process gas inlet 214 is configuredto direct the process gas in a generally radially inward direction. Assuch, in some embodiments, the process gas inlet 214 is a side gasinjector. The side gas injector is positioned to direct the process gasacross a surface of the susceptor 206 and/or the substrate 202. During afilm formation process for forming a film layer of the substrate 202,the susceptor 206 is located in the processing position, which isadjacent to and at about the same elevation as the process gas inlet214, thus allowing the process gas to flow generally along flow path 273across the upper surface of the susceptor 206 and/or substrate 202. Theprocess gas exits the process gas region 236 (along flow path 275)through the gas outlet 216 located on the opposite side of the processchamber 200 from the process gas inlet 214. Removal of the process gasthrough the gas outlet 216 here is facilitated by a vacuum pump 257coupled thereto.

Purge gas supplied from a purge gas source 262 is introduced to thepurge gas region 238 through a purge gas inlet 264 formed in thesidewall of the body 212. The purge gas inlet 264 is disposed at anelevation below the process gas inlet 214. The purge gas inlet 264 isconfigured to direct the purge gas in a generally radially inwarddirection. The purge gas inlet 264 may be configured to direct the purgegas in an upward direction. During a film formation process, thesusceptor 206 is located at a position such that the purge gas flowsgenerally along flow path 265 across a back side of the susceptor 206.The purge gas exits the purge gas region 238 (along flow path 266) andis exhausted out of the process chamber through the gas outlet 216located on the opposite side of the process chamber 200 as the purge gasinlet 264.

The process chamber 200 further includes a spot heating module 271. Thespot heating module 271 may be the spot heating module 104 shown in FIG.1 . The spot heating module 271 includes one or more spot heaters 270.The spot heater 270 may be the spot heater 110 shown in FIG. 1 . Thespot heating module 271 is utilized to spot heating cold spots on thesubstrate 202 during processing. Cold spots may be formed on thesubstrate 202 at locations that the substrate 202 is in contact with thelift pins 232.

The above-described process chamber 200 can be controlled by a processorbased system controller, such as controller 247, shown in FIGS. 2 and 3. For example, the controller 247 is configured to control flow ofvarious precursor and process gases and purge gases from gas sources,during different operations of a substrate processing sequence. By wayof further example, the controller 250 is configured to control a firingof the spot heating module 271, predict an algorithm for firing the spotheating module 271, and/or encode or synchronize the operation of thespot heating module 271 with substrate rotation, feeding of gases, lampoperation, or other process parameters, among other controlleroperations. The controller 247 includes a programmable centralprocessing unit (CPU) 252 that is operable with a memory 255 and a massstorage device, an input control unit, and a display unit (not shown),such as clocks, cache, input/output (I/O) circuits, and the like,coupled to the various components of the process chamber 200 tofacilitate control of substrate processing in the process chamber 200.The controller 247 further includes support circuits 258. To facilitatecontrol of the process chamber 200 described above, the CPU 252 may beone of any form of general purpose computer processor that can be usedin an industrial setting, such as a programmable logic controller (PLC),for controlling various chambers and sub-processors. The memory 255 isin the form of computer-readable storage media that containsinstructions, that when executed by the CPU 252, facilitates theoperation of the process chamber 200. The instructions in the memory 255are in the form of a program product such as a program that implementsthe method of the present disclosure.

FIG. 4 is a schematic cross sectional side view of a process chamber 400according to one embodiment. The process chamber 400 may be the processchamber 102 shown in FIG. 1 . The process chamber 400 is configured toprocess one or more substrates, including the deposition of a materialon a deposition surface 422 of a substrate 410. The process chamber 400includes a first energy transmissive member 412, a second energytransmissive member 414, and a substrate support 402 disposed betweenthe first energy transmissive member 412 and the second energytransmissive member 414. The first energy transmissive member 412 andthe second energy transmissive member 414 may be fabricated from thesame material as the first energy transmissive member 208 and the secondenergy transmissive member 210 shown in FIG. 2 .

The substrate support 402 here includes a susceptor 424 for supportingthe substrate 410 and a susceptor support 426 for supporting thesusceptor 424. The substrate 410 is brought into the process chamber 400through a loading port 428 and positioned on the susceptor 424. Thesusceptor 424 may be made of SiC coated graphite. The susceptor support426 is here rotated by a motor (not shown), which in turn rotates thesusceptor 424 and the substrate 410.

The process chamber 400 includes a first plurality of heating elements406, such as radiant heating lamps, disposed below the second energytransmissive member 414 for heating the substrate 410 from below thesubstrate 410. The process chamber 400 also includes a second pluralityof heating elements 404, such as radiant heating lamps, disposed overthe first energy transmissive member 412 for heating the substrate 410from above the substrate 410. In one embodiment, the first and secondplurality of heating elements 404, 406 provide infrared radiant heat tothe substrate though the first energy transmissive member 412 and thesecond energy transmissive member 414, respectively. The first andsecond energy transmissive members 412, 414 are optically transparent tothe wavelength of the energy from the heating elements 404, 406, forexample infrared radiation emitted by lamps, transparent defined hereinas transmitting at least 95% of the received infrared radiation.

In one embodiment, the process chamber 400 also includes one or moretemperature sensors 430, such as optical pyrometers, which are used tomeasure temperatures within the process chamber 400 and on the surface422 of the substrate 410. The one or more temperature sensors 430 aredisposed on a support member 432 that is disposed on a cover 416. Areflector 418 is placed outside the first energy transmissive member 412to reflect infrared light radiating from the substrate 410 and the firstenergy transmissive member 412 back towards the substrate 410. A spotheating module 407 is disposed on the support member 432. The spotheating module 407 may be the spot heating module 104 shown in FIG. 1 .The spot heating module 407 includes one or more spot heater 408. Thespot heater 408 may be the spot heater 110 shown in FIG. 1 . The spotheating module 407 produces one or more high-energy radiant beams 434,such as focused high-energy radiant beams, for example laser beams,which form one or more beam spots on the surface 422 of the substrate410 in order to perform localized heating of the substrate 410. Wherethe spot heating module 407 is located above the reflector 418, the oneor more high-energy radiant beams 434 pass through an opening 420 formedin an annular portion 436 of the reflector 418, and the first energytransmissive member 412 is optically transparent to the wavelength ofthe high-energy radiant beams (transmitting at least 95% of the receivedradiation of the high-energy radiant beam 434).

During operation, such as an epitaxial deposition process, the substrate410 is heated to a predetermined temperature, such as less than about750 degrees Celsius. Despite the precise control of heating thesubstrate 410, one or more regions on the substrate 410 may experiencetemperature non-uniformity, such as being about 2-5 degrees Celsiuslower than rest of the substrate 410. This temperature non-uniformityleads to non-uniformity in the deposited film thickness, such as athickness non-uniformity of one percent or more in a film deposited onthe substrate. In order to improve the temperature uniformity of thesubstrate, which in turn reduces the film thickness non-uniformity, thespot heating module 407 is used to locally heat one or more regions onthe substrate 410. Since the substrate 410 is rotating during operation,the localized heating by the spot heating module 407 may occur be overan annular region at a certain radius of the substrate 410.

The temperature sensor 430 may be used to modulate power to the spotheating module 407. For example, a controller (not shown) may receivetemperature data from the temperature sensor 430, and may increase orreduce power to the spot heating module 407 based on the temperaturedata. In such a system, the combination of temperature sensor 430 andspot heating module 407 can be used in closed-loop or open-loop controlto adjust the spot heating module 407 based on a reading from thetemperature sensor 430.

FIG. 5 is a schematic cross sectional side view of a process chamber 500according to another embodiment. The process chamber 500 may be theprocess chamber 102 shown in FIG. 1 . The process chamber 500 maygenerally have the shape of a rectangular box. The process chamber 500includes a first energy transmissive member 502, a second energytransmissive member 504, and a region 503 defined by the first andsecond energy transmissive members 502, 504 and therebetween. The firstenergy transmissive member 502 and the second energy transmissive member504 may be fabricated from the same material as the first energytransmissive member 208 and the second energy transmissive member 210shown in FIG. 2 . In the embodiment of FIG. 5 , the first and secondenergy transmissive members 502 and 504 are flat, and made of quartztransparent to the wavelength of energy to be passed therethrough toheat a substrate.

A first plurality of radiant heat sources 510 is disposed over the firstenergy transmissive member 502. The first plurality of radiant heatsources 510 here are be elongated tube-type radiant heating elements.The radiant heat sources 510 are disposed in spaced-apart parallelrelationship and also extend substantially parallel to a reactant gasflow path (shown by arrow 512) through the process chamber 500. A secondplurality of radiant heat sources 515 is positioned below the secondenergy transmissive member 504, and oriented transverse to the firstplurality of radiant heat sources 510. A plurality of spot heat sources520 supply concentrated heat to the underside of the substrate supportstructure (described below), to counteract a heat sink effect created bycold support structures extending through the bottom of the processchamber 500. A spot heating module 513 is disposed on a cover 506located over the first plurality of radiant heat sources 510. The spotheating module 513 may be the spot heating module 104 shown in FIG. 1 .The spot heating module 513 includes one or more spot heaters 511. Thespot heater 511 may be the spot heater 110 shown in FIG. 1 . The spotheating module 513 produces one or more high-energy radiant beams toperform localized heating of a substrate disposed in the process chamber500. As is known in the art of semiconductor processing equipment, thepower of the various heat sources 510, 511, 515, 520 can be controlledindependently or in grouped zones in response to the substratetemperature measured through temperature sensors.

A substrate 525 is shown supported by a substrate support 530 disposedin the region 503. The substrate support 530 includes a substrate holder532, upon which the substrate 525 rests, and a support spider 534. Thespider 534 is mounted to a shaft 536, which extends downwardly through atube 538 extending through a chamber bottom 508. The tube 538communicates with a source of purge gas which can flow therethroughduring processing of the substrate 525. A plurality of temperaturesensors is positioned in proximity to the substrate 525. The temperaturesensors may take a variety of forms, such as optical pyrometers orthermocouples. In the illustrated embodiment, the temperature sensorscomprise thermocouples, including a first or central thermocouple 540,suspended below the substrate holder 532 in any suitable fashion. Thecentral thermocouple 540 passes through the spider 534 in proximity tothe substrate holder 532. The process chamber 500 further includes aplurality of secondary or peripheral thermocouples, also in proximity tothe substrate 525, including a leading edge or front thermocouple 545, atrailing edge or rear thermocouple 550, and a side thermocouple (notshown). Each of the peripheral thermocouples is housed within a slipring 552, which surrounds the substrate holder 532 and the substrate525. The slip ring 552 rests upon support members 554, which extend froma front chamber divider 556 and a rear chamber divider 558. The dividers556, 558 are fabricated from quartz. Each of the central and peripheralthermocouples are connected to a temperature controller, which sets thepower of the various heat sources 510, 515, 520 in response to thetemperature readings from the thermocouples.

The process chamber 500 further includes an inlet port 560 for theinjection of reactant and carrier gases, and the substrate 525 can alsobe received therethrough. An outlet port 564 is on the opposite side ofthe process chamber 500, with the substrate support 530 positionedbetween the inlet port 560 and outlet port 564. An inlet component 565is fitted to the process chamber 500, adapted to surround the inlet port560, and includes a horizontally elongated slot 567 through which thesubstrate 525 can be inserted. A generally vertical inlet 568 receivesgases from gas sources and communicates such gases with the slot 567 andthe inlet port 560. An outlet component 570 similarly mounts to theprocess chamber 500 such that an exhaust opening 572 aligns with theoutlet port 564 and leads to exhaust conduits 574. The conduits 574, inturn, can communicate with suitable vacuum means (not shown) forexhausting process gases from the process chamber 500. The processchamber 500 also includes a source 576 of excited species, positionedbelow the chamber bottom 508. The excited species source 576 may be aremote plasma generator disposed along a gas line 578. A source ofprecursor gases 580 is coupled to the gas line 578 for introduction intothe excited species source 576. A source of carrier gas 582 is alsocoupled to the gas line 578. One or more branch lines 584 can also beprovided for additional reactants. The excited species source 576 can beemployed for plasma enhanced deposition, but also may be utilized forexciting etchant gas species for cleaning the process chamber 500 ofexcess deposition material when no substrate is in the process chamber500.

FIGS. 6A-6B are schematic top views of the spot heating module 104according to embodiments of the present disclosure. As shown in FIG. 6A,the spot heating module 104 includes one or more spot heaters 110. Theone or more spot heaters 110 are disposed on a support 610 that isintegrated into or on a chamber cover 602. The chamber cover 602 may bethe reflector 254 of the process chamber 200 shown in FIGS. 2 and 3 ,the cover 416 of the process chamber 400 shown in FIG. 4 , or the cover506 of the process chamber 500 shown in FIG. 5 . Each spot heater 110includes a stage 604 disposed on the support 610 and a collimator 606disposed on the stage 604. The one or more collimators 606 are connectedto the one or more high-energy radiant sources 106 via one or morefibers 108 shown in FIG. 1 . One or more sensors 608, such aspyrometers, are disposed on the support 610. In some embodiments, eachspot heater 110 includes the collimator 606 and the sensor 608, and boththe collimator 606 and the sensor 608 are disposed on a single stage604, as shown in FIG. 6B. In some embodiments, the collimator 606 isreplaced with a high-energy radiant source, such as a laser or laserdiode, and each spot heater 110 includes a high-energy radiant sourcedisposed on the stage 604.

The collimator is an optical element that collimates radiation from oneof the high-energy radiant sources, for example by use of appropriatelydesigned lenses. The collimator has a first end, into which radiationfrom a radiant source is input, for example by directing the output of alaser source into an opening in the first end. The collimator may have asecond end with an opening where a collimating lens is housed. Differentsize collimators may be used to form different sized beams of radiation,if desired. The stage 604 may have a mounting feature, such as abracket, that is adjustable in size to accommodate collimators ofdifferent sizes that can be swapped out to give heating spots that aredifferent sizes.

In other embodiments, a laser may be directly mounted to the collimatorby inserting a beam exit portion of the laser into the first end of thecollimator such that the radiation emitted by the laser passes throughthe collimator and exits through the second end with the collimatinglens.

FIGS. 7A-7B are perspective views of a mounting bracket 700 for mountingthe spot heating module 104 according to embodiments hereof. In someembodiments, the spot heaters 110 of the spot heating module 104 arecoupled to the mounting bracket 700 instead of the support 610, so thespot heaters 110 can be conveniently added to or removed from a processchamber. Because the spot heaters 110 and the sensors 608 are coupled todifferent components, the addition or removal of the spot heaters 110will not affect the sensors 608. In one embodiment, as shown in FIG. 7A,the mounting bracket 700 includes an annular portion 705 surrounding acentral opening 702 and one or more plates 704 extending from theannular portion 705. Each plate 704 has an opening 706 formed thereinallowing the high-energy radiation produced by the spot heater 110 topass through. The number of plates 704 extending from the annularportion here correspond to the number of spot heaters 110. In oneembodiment, there are four spot heaters 110, and each spot heater 110 iscoupled to a corresponding plate 704. The central opening 702 and/or thespace between adjacent plates 704 may be utilized to accommodate one ormore sensors 608 between adjacent plates 704. The mounting bracket 700is secured to the one or more components of the process chamber 102 by aplurality of securing devices 708.

FIG. 7B is a perspective view of a mounting bracket according to anotherembodiment. In some embodiments, the mounting bracket of FIG. 7Bincludes a body 710 having an inner edge 712 and an outer edge 714. Inone embodiment, the body 710 is annular. In another embodiment, the body710 is rectangular. The inner edge 712 defines an opening 716. One ormore openings 718 are formed through the body 710 between the inner edge712 and the outer edge 714 thereof. Each spot heater 110 is coupled tothe mounting bracket 700 at a location surrounding an opening 718, sothe high-energy radiant beam produced by the spot heater 110 can passthrough the opening. In some embodiments, there are more openings 718than the spot heaters 110, and the extra openings 718 and/or the opening716 may be utilized to accommodate one or more sensors 608 in theopenings 716 and 718.

FIG. 8 is an exploded view of the mounting bracket 700 secured tocomponents of a process chamber according to one embodiment. In oneembodiment, the process chamber is the process chamber 400. As shown inFIG. 8 , the mounting bracket 700 is disposed on the support 610, thesupport 610 is disposed on the reflector 418, and the reflector 418 issurrounded by another support 808. The support 808 may be secured to theprocess chamber 400. Each plate 704 includes an opening 801 that isaligned with a corresponding opening 802 formed in the support 610, acorresponding opening 806 formed in a flange portion 804 of thereflector 418, and a corresponding opening 810 formed in the support808. The aligned openings 801, 802, 806, 810 are utilized to secure themounting bracket 700 with the securing devices 708. The support 610includes a plurality of openings 803 that are aligned with the openings706 (FIG. 7A) to allow the high-energy radiation produced by the spotheater 110 to pass through.

In one embodiment, the securing device 708 is a single screw extendingthrough the openings 801, 802, 806, 810, and the single threadedfastener is secured to the mounting bracket 700 and the support 808 by asecuring mechanism, such as a nut. In another embodiment, as shown inFIG. 8 , the securing device 708 includes a first piece 812 disposedbetween the support 610 and the reflector 418 and a second piece 814disposed between the flange portion 804 of the reflector 418 and thesupport 808. The first piece 812 includes a first threaded rod 816 and asecond threaded rod 818 opposite the first threaded rod 816, and thesecond piece 814 includes a first end 820 and a second end 822 oppositethe first end 820. The first threaded rod 816 extends through theopening 802 of the support 610 and the opening 801 of the mountingbracket 700, and the first threaded rod 816 is secured to the mountingbracket 700 by a securing mechanism, such as a nut. The second threadedrod 818 of the first piece 812 extends through the opening 806 formed inthe flange portion 804 of the reflector 418. The second threaded rod 818of the first piece 812 is configured to be inserted into, and securedby, the first end 820 of the second piece 814. The second end 822 of thesecond piece 814 extends through the opening 810 formed in the support808 and is secured to the support 808. By securing the mounting bracket700 to the support 808, physical stability of the mounting bracket 700and the spot heaters 110 is improved.

FIG. 9 is a schematic top view of the spot heating module 104 mounted toa process chamber 900 according to one embodiment. The process chamber900 may be the process chamber 200 shown in FIG. 2 . The process chamber900 includes a susceptor 904 having a plurality of through holes 906 fora plurality of lift pins (not shown) to extend therethrough. Thesusceptor 904 may be the susceptor 206 of the process chamber 200 shownin FIG. 2 , and the through holes 906 may be the through holes 207 ofthe process chamber 200 shown in FIG. 2 . As shown in FIG. 9 , the oneor more spot heaters 110 of the spot heating module 104 are coupled tothe mounting bracket 700, and the mounting bracket 700 is secured to thesupport 808. During an alignment process, any components between themounting bracket 700 and the susceptor 904 may be removed, so anoperator can view a guide beam produced by the spot heater 110 landingon the susceptor 904. The susceptor 904 may be rotated so the region tobe heated by the spot heater is pointed to by the guide beam. The guidebeam may be produced by a lower intensity laser directly coupled, orfiber-coupled, to the spot heater 110.

FIG. 10 is a schematic side view of the spot heater 110 according to oneembodiment. As shown in FIG. 10 , the spot heater 110 includes thecollimator 606 held by a collimator holder 1002. The collimator holder1002 is disposed on the stage 604, and the stage 604 is disposed on themounting bracket 700. The stage 604 includes a slider 1004 and a wedge1006. The slider 1004 is movable linearly on the mounting bracket 700using set screws or an actuator. The wedge 1006 includes a surface 1008that is in contact with the collimator holder 1002, and the surface 1008forms an angle A with respect to a plane 1010 that is substantiallyparallel to a major surface of the susceptor, such as the susceptor 206of the process chamber 200 shown in FIG. 2 . In one embodiment, theangle A of the wedge 1006 is set, and a plurality of wedges havingdifferent angles A are utilized to adjust the guide beam. The angle Amay range from about one degree to about 30 degrees. In anotherembodiment, the angle A of the wedge 1006 is adjustable by an actuatorlocated in the wedge 1006. Targeting of the spot heater 110 can beaccomplished by selecting the angle A of the wedge 1006 and by adjustingthe location of the slider 1004. The guide beam described above can beactivated, and the slider 1004 adjusted, to bring the radiation of thespot heater 110 to a selected location for processing.

As noted above, collimators of different sizes may be used with the spotheater of FIG. 10 . An optional adapter 1012 may be used in thecollimator holder 1002 to effectively reduce the size of the openingwithin the collimator holder 1002 to fit a smaller collimator 606. Inthis way, collimators of different sizes can be swapped into the spotheater 110 of FIG. 6 to allow beam spots of different sizes to be used.The adapter 1012 is shown in FIG. 10 as a cylinder, but the adapter 1012could be a generally cylindrical or ring-like member that is insertedinto the collimator holder 1002, thus reducing the diameter of thecollimator holder 1002. A ring-link adapter 1012 could fit into thecollimator holder 1002 at the upper end, where the opening accommodatesinsertion of the collimator 606, in a middle region, or at the lower endwhere the collimator holder 1002 contacts the wedge 1006. Using anadapter such as the adapter 1012 enables use of a smaller collimatorthat fits the inner diameter of the adapter 1012 in the collimatorholder 1002.

Benefits of the present disclosure include a reduction in the number ofcold spots associated with a substrate. Reducing the temperaturenon-uniformities within a substrate further creates a substrate with amore uniform surface. A cost reduction is also realized in that there isan increase in substrate quality. Additional benefits include preciselocal heating of the substrate for ultra-fine tuning of temperatureuniformity.

FIGS. 11A-11B are schematic views of a beam spot formed by one or morespot heaters 110 according to one embodiment. As shown in FIG. 11A, abeam spot 1102 is formed by one spot heater 110 (FIG. 10 ). The beamspot 1102 may be too small to achieve the localized heating of asubstrate. The beam spot 1102 can be modified without making changes tothe optics of the spot heater 110. For example, as shown in FIG. 11B, abeam spot 1104 is formed by two spot heaters 110 (FIG. 10 ). The twospot heaters 110 are positioned so the beam spots produced by the spotheaters 110 overlap.

FIGS. 12A-12B are schematic views of a beam spot having differentorientations with respect to the movement of a substrate according toone embodiment. As shown in FIG. 12A, a beam spot 1202 has a shape of anellipse. In one embodiment, the major axis of the ellipse shaped beamspot 1202 is substantially perpendicular to the direction of thesubstrate movement, as indicated by arrow 1204. When the major axis ofthe beam spot 1202 is substantially perpendicular to the direction ofthe movement of the substrate, the beam spot 1202 has a wide width. Thewidth of the beam spot 1202 can be adjusted without making changes tothe optics of the spot heater 110. In one embodiment, the width of thebeam spot 1202 can be changed by rotating the collimator 606 (FIG. 10 ).As shown in FIG. 12B, the rotation of the collimator 606 causes the beamspot 1202 to rotate. Thus, the major axis of the ellipse shaped beamspot 1202 is not substantially perpendicular to the direction of themovement of the substrate, leading to a narrower width of the beam spot1202.

In summation, embodiments described herein provide an epitaxialdeposition chamber which includes a spot heating module for providinglocalized heating of a substrate during processing. Energy may befocused to about a area during substrate rotation within the chamber inorder to locally heat and tune specific locations of the substrate, suchas locations adjacent a lift pin, at specifically timed intervals. Insome cases, the spot heating elements can be targeted to specificlocations by measuring deposition thickness profile of a test substrate,finding locations of the test substrate that would have benefitted fromspot heating, marking those locations on the test substrate,re-inserting the test substrate into the chamber, and using thetargeting functionality (guide beam and positioning adjustments)described herein to direct the spot heating to the marked locations.Subsequent substrates can then be spot heated by the targeted spotheating elements to address systematic processing non-uniformities.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

1. A process chamber, comprising: a chamber body; a substrate supportdisposed in the chamber body; a support disposed outside the chamberbody; a mounting bracket disposed on the support outside the chamberbody; and a plurality of spot heating modules each comprising a movablestage and coupled to the mounting bracket, the mounting bracketincluding a plurality of openings formed therein, wherein each openingof the plurality of openings is positioned between a respective spotheating module of the plurality of spot heating modules and thesubstrate support, wherein the movable stage includes a slider and awedge.
 2. The process chamber of claim 1, wherein each spot heatingmodule of the plurality of spot heating modules comprises a laser sourceand a plurality of collimators, wherein each collimator is opticallycoupled to a respective laser source by an optical fiber.
 3. The processchamber of claim 1, further comprising a reflector located adjacent tothe mounting bracket.
 4. The process chamber of claim 3, wherein thereflector includes a plurality of openings formed therein, each openingof the plurality of openings of the reflector positioned between thesubstrate support and a respective spot heating module of the pluralityof spot heating modules.
 5. The process chamber of claim 1, wherein themounting bracket is planar.
 6. The process chamber of claim 1, whereinthe mounting bracket includes an annular portion surrounding a centralopening, and one or more plates extending from the annular portion. 7.The process chamber of claim 1, further comprising a plurality ofsensors disposed on the mounting bracket, each sensor of the pluralityof sensors corresponding to a respective spot heating module of theplurality of spot heating modules, and wherein each sensor of theplurality of sensors is a pyrometer.
 8. The process chamber of claim 1,wherein each spot heating module of the plurality of spot heatingmodules is a laser source.
 9. A process chamber, comprising: a chamberbody; a substrate support disposed in the chamber body; a supportdisposed outside the chamber body; a mounting bracket disposed on thesupport outside the chamber body; and a plurality of spot heatingmodules coupled to the mounting bracket, each spot heating modulecomprising a movable stage coupled to the mounting bracket, wherein themovable stage includes a slider and a wedge.
 10. The process chamber ofclaim 9, wherein a respective sensor of a plurality of sensors ismounted on each movable stage.
 11. The process chamber of claim 9,wherein the mounting bracket including a plurality of openings formedtherein at different angular positions with respect to a center of themounting bracket, wherein each opening of the plurality of openings ispositioned between a respective spot heating module of the plurality ofspot heating modules and the substrate support.
 12. The process chamberof claim 11, wherein each opening of the openings in the mountingbracket is aligned with a corresponding opening formed in the supportdisposed outside the chamber body.
 13. The process chamber of claim 9,wherein the mounting bracket includes an annular portion surrounding acentral opening, and one or more plates extending from the annularportion.
 14. A spot heating assembly, comprising: a support; a mountingbracket disposed on the support; a plurality of spot heating modulescoupled to the mounting bracket, wherein the mounting bracket comprises:an annular portion surrounding a central opening; and a plurality ofopenings formed in the mounting bracket, wherein each opening of theplurality of openings is positioned adjacent to a respective spotheating module of the plurality of spot heating modules, wherein eachspot heating module of the plurality of spot heating modules is disposedon a respective movable stage.
 15. The spot heating assembly of claim14, further comprising a slider that is linearly movable on the mountingbracket.
 16. The spot heating assembly of claim 14, wherein each openingof the openings in the mounting bracket is aligned with a correspondingopening formed in the support.
 17. The spot heating assembly of claim14, wherein each spot heating module of the plurality of spot heatingmodules comprises a laser source and a plurality of collimators, eachcollimator optically coupled to a respective laser source by an opticalfiber.
 18. The spot heating assembly of claim 14, wherein the mountingbracket further comprises a plurality of plates extending from theannular portion, and wherein each spot heating module of the pluralityof spot heating modules is coupled to one of the plurality of plates.19. The spot heating assembly of claim 18, further comprising aplurality of sensors, wherein each sensor of the plurality of sensors isdisposed on the respective movable stage.
 20. The spot heating assemblyof claim 19, wherein each sensor of the plurality of sensors is apyrometer.